import {v4 as uuidv4} from 'uuid'
//生成一个随机的字符串， 且每次执行不能发生变化， 游客身份保存持久性
export const getUUID = () => {
  //先从本地存储获取uuid
  let uuid_token = localStorage.getItem('UUIDTOKEN');
  //如果没有
  if(!uuid_token) {
    //生成游客临时身份
    uuid_token = uuidv4();
    localStorage.setItem('UUIDTOKEN', uuid_token)
  }
  return uuid_token
}